Many kinds of removable band-type couplings for pipes exist in the art. It is noted that throughout the specification and claims, the term “pipe” encompasses any kind of generally cylindrical object.
U.S. Pat. No. 6,293,556 to Krausz describes a coupling for connecting pipes of the same or different diameters. The coupling has a ring shaped seal made of rubber or other resilient material, constructed of a first ring seal seated over a second ring seal. The seals can be easily disconnecting from one another to allow sealing against different diameter pipes. For smaller diameter pipes, both the first and second ring seals are used; for larger diameters, only one seal is used.
However, in some applications, the seals are subjected to considerable axial forces due to the fluids flowing in the pipe, sealing forces, clamping forces and other factors. It would be desirable to improve the ability of the seal to withstand such axial forces.